How to Choose Base Layers
REI Co-op Lightweight Long Underwear Crew Top - Men's
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This lightweight shirt efficiently manages moisture so you will be comfortable when you're having some serious fun out there.
Shop similar products- Made of a soft polyester that wicks sweat and dries fast
- Flatseam construction, raglan sleeves and side gussets are comfortable as you move
- Lower back hem stays tucked in when you lean forward
- UPF 35 sun protection
- Next-to-skin fit
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
| Best Use | Multisport |
|---|---|
| Shirt Type | T-shirt |
| Fabric | Polyester |
| Sun-Protective Fabric | Yes |
| UPF Rating | 35 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Lightweight |
| Sleeve Length | Long Sleeve |
| Gender | Men's |
| Sustainability | From a Climate Label Certified brand |
REI Co-op Clothing - Men's
| XS | S | M | L | XL | XXL | XXXL | 24 IN Waist | 26 IN Waist | 28 IN Waist | 30 IN Waist | 31 IN Waist | 32 IN Waist | 33 IN Waist | 34 IN Waist | 35 IN Waist | 36 IN Waist | 38 IN Waist | 40 IN Waist | 42 IN Waist | 44 IN Waist | 46 IN Waist | 48 IN Waist | 50 IN Waist | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chest | 35 | 36 - 38 | 39 - 41 | 42 - 45 | 46 - 49 | 50 - 53 | 54 - 57 | |||||||||||||||||
| Sleeve Length | 32 | 32.5 | 33 | 33.5 | 34 | 34.75 | 35.5 | |||||||||||||||||
| Waist | 27.5 | 28 - 30 | 32 - 34 | 36 - 38 | 40 - 42 | 44 - 46 | 48 - 50 | 24 | 26 | 28 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 |
| Hip | 33.5 | 34.5 - 36.5 | 37.5 - 39.5 | 41 - 43 | 44 - 46.5 | 47.5 - 50.5 | 51.5 - 54.5 | 32 | 33.5 | 34.5 | 36.5 | 37 | 37.5 | 38.5 | 39.5 | 40.25 | 41 | 43 | 44 | 46.5 | 47.5 | 50.5 | 52.5 | 54.5 |
| Inseam | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 |
Sizing Notes
Measurements are stated in inches unless otherwise indicated. Size chart values represent body measurements, not garment measurements.
SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes.
TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.
Capri or cropped pants have an intentionally shorter inseam—reference the technical specs instead of this chart.
Inseam is measured to the floor.
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Most Helpful Favorable Review
Great value and comfortable.
JMcQuay9 years ago
I picked this top up on a whim at a REI in Montana. I used it as an outer layer for a three day rifle match in the sun and heat. The top wicked well. It was very comfortable and breaths well. The way it managed sweat, I have no doubt it will work well as a base layer in the cold. After dragging a pack around and rolling on the ground for three days, the shirt still looked new. An excellent deal and compares well to Patagonia. It manages odor well. I was camping out for the match so no chance to shower or do laundry. Once I got back home I ordered a second. This may be my regular backpacking shirt. I just wish the orange was in stock. The blue looks great though!
JMcQuay
Evansville, IN, United States
5 people found this review helpful
Most Helpful Critical Review
Beware - Product Image is Incorrect
Norm Nihon9 years ago
Over the past six months, I have purchased two of the REI Lightweight Crew Tops from one of our local REI outlets. I have been pleased with the comfort and simplicity of the tops and feel at ease wearing them in and around town for a wide variety of occasions.
Wanting to purchase another, I placed an order online. Upon delivery, I was surprised (shocked) to find a not-so-discreet REI logo above the left chest. Needless to say, I will be returning the top ASAP and refrain from purchasing any REI branded products online in the future.
If I can't have confidence in the correctness of REI's website and want a top cheapened to look like something from a mall t-shirt transfer shop, I will wait until the opportunity presents itself to shop at one of REI's outlets and place eyes on the product first.
Norm Nihon
Denver
5 people found this review helpful
Customer Images
JMcQuay
Evansville, IN, United States
Great value and comfortable.
9 years ago
I picked this top up on a whim at a REI in Montana. I used it as an outer layer for a three day rifle match in the sun and heat. The top wicked well. It was very comfortable and breaths well. The way it managed sweat, I have no doubt it will work well as a base layer in the cold. After dragging a pack around and rolling on the ground for three days, the shirt still looked new. An excellent deal and compares well to Patagonia. It manages odor well. I was camping out for the match so no chance to shower or do laundry. Once I got back home I ordered a second. This may be my regular backpacking shirt. I just wish the orange was in stock. The blue looks great though!
Yes , I recommend this product
Girion
Orange County, CA
Great base layers
10 years ago
I purchased the lightweight and midweight long sleeve base layers in advance of a long weekend backpacking trip to Santa Rosa Island. Was looking for something to keep the sun off during the day hikes and keep me warm during the cool windy nights (temps ranged between 75 during the day to low 50s at night) these were the real deal. I was originally looking at the Capilene base layers but wasn't thrilled with the fit. The rep at REI suggested these, so I tried a few sizes on. For me (6 foot, 175lbs) the large was the perfect fit. Its fitted, so not too loose and not too snug. They wore well under a day pack, and dried fast after between 7-14 miles on the trails. The midweight was great under a fleece in the evenings and I used it as my sleeping layer as well and was comfortable all night long. Got the blue and titanium and now wear them around the house and out in the mild SoCal evenings. Good product and value.
Yes , I recommend this product
ILovePlastic
Austin, TX, United States
Good baselayer, better than short sleeve version.
8 years ago
I really like the fit and function of this shirt. The short sleeved version got my hopes up to use as a workout shirt, but these are clearly lightweight long underwear/baselayers. It makes more sense to get the long sleeved version with this use in mind Very nice shirt. Will probably last forever. Be mindful of the pattern (see pic).
Yes , I recommend this product
Tyson Kamp
los gatos, ca
Not Wicking
8 years ago
These shirts fit me well and are comfortable when they're dry. However I did a hike in slightly windy 50-55 degrees, 2k feet up in about 1:45 so I was sweating pretty good. When I took my pack off at the top for about 10 minutes, I was getting really cold as the shirt wasn't drying. When I put the pack back on it was very cold and unpleasant. We pushed a good pace down and the shirt basically never dried. A friend suggested never using fabric softener and always using Dr. Bronners or some such soap that will not clog the fabric and reduce its ability to wick, so I will see if that helps. They shirt has been washed only twice maybe prior to my experience. It was hard to pass up at the sale price and if the wicking never improves I'll still wear them, just not when I'm going to be working really hard. I'd recommend this at the sale price but not for hard hiking (at any price).
Yes , I recommend this product
Diegotheengineer
Georgia
Good base layer for cooler temps
9 years ago
I used this on the AT trail on a weekend when the temperatures dipped into the high 20's. The top kept me warm during morning and afternoon hikes when temperatures were changing through the 30s and 40s. At night extra clothing was needed to stay warm. The fabric breathes well and moved with my larger body frame without any issues. This is great base layer shirt that can be used for heavy activity.
Joseph Esposito
Reading MA
Not Thrilled
9 years ago
Besides the fact this is 100% polyester which is not ideal... i have a serious gripe with this shirt. For some idiotic reason, every base layer (from all brands not just REI) have a ridiculous amount of seams. I know they are "flat seams" but they are still very uncomfortable when pressed tight to my body (like with this shirt) and i don't understand why the manufacturers chose to make so many seams. Is it for looks? idk, but i wish there was even a single baselayer shirt without so many seams at REI today
Norm Nihon
Denver
Beware - Product Image is Incorrect
9 years ago
Over the past six months, I have purchased two of the REI Lightweight Crew Tops from one of our local REI outlets. I have been pleased with the comfort and simplicity of the tops and feel at ease wearing them in and around town for a wide variety of occasions. Wanting to purchase another, I placed an order online. Upon delivery, I was surprised (shocked) to find a not-so-discreet REI logo above the left chest. Needless to say, I will be returning the top ASAP and refrain from purchasing any REI branded products online in the future. If I can't have confidence in the correctness of REI's website and want a top cheapened to look like something from a mall t-shirt transfer shop, I will wait until the opportunity presents itself to shop at one of REI's outlets and place eyes on the product first.
Minston
MD
Rough on the nipples
9 years ago
Good wicking, but after my first run (1 hour +), my nipples were sore for two days. Doesn't happen with cotton. I'm not heavy, or sporting moobs, but the material isn't very soft. For a shorter run it might be fine.
RangerRobAZ
Phoenix, AZ
Great fit, price, and look
9 years ago
Best shirt I've owned for awhile. It fits (long sleeves and bottom of shirt). It is not bulky. Feels great and was a super price.
rappleg6
soft, fits true to size
9 years ago
I like this shirt. It was very soft. It was for a good price as well. Thanks
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